Abstract: Apparatus and method for testing TIG (tungsten inert gas) welds of end plugs on a sealed nuclear reactor fuel rod. An X-ray fluorescent spectrograph testing unit detects tungsten inclusion weld defects in the top end plug's seal weld. Separate ultrasonic weld inspection system testing units test the top end plug's seal and girth welds and test the bottom end plug's girth weld for penetration, porosity and wall thinning defects. The nuclear fuel rod is automatically moved into and out from each testing unit and is automatically transported between the testing units by rod handling devices. A controller supervises the operation of the testing units and the rod handling devices.

Abstract: The radioactivity of radioactive fluid is monitored, in the presence of background radiation, without interruption of radioactivity detection with two successive volumes of radioactive fluid, the background being eliminated by subtraction. Typically the intrinsic responses are in the ratio of two to one for such successive measurements, when the proper volumes have been selected.

Abstract: Apparatus for remotely controlled examination of the control rod drive penetration stub tubes in the wall of a nuclear reactor pressure vessel including a rotatable carriage on which is mounted a reciprocable shaft to which is attached an inspection instrument for scanning the stub tubes.

Abstract: A stopper apparatus for use in blocking the unvalved nozzle of a cooling fluid filled nuclear reactor pressure vessel includes a plug, typically in the shape of a frusto-conical member having inflatable gaskets for sealing against a seat of generally unknown surface characteristics and means for positioning and urging the plug into position to seal the nozzle. The plug is typically positioned by suspension cables whereby the apparatus can be temporarily inserted and removed from the pressure vessel. The urging means is generally a two-way hydraulically driven jack controlled by remotely-actuated hydarulic lines. The apparatus is a tool which permits temporary sealing of a submerged outlet in a reactor vessel to permit maintenance on a fluid recirculation loop.

Abstract: Device for shutting down a high-temperature nuclear reactor having a reactor core, including a reflector disposed outside the reactor core, channels being disposed in the reflector and having lower ends, storage bins being disposed above the reactor core and being in communication with the channels above the lower ends thereof, a neutron-absorbing material formed of fluidic bodies being storable in the storage bins and feedable into the channels, a plurality of lines connected between the lower ends of the channels and the storage bins, means for selectively establishing an upwardly directed fluid flow of the material in one of the plurality of lines for conveying the neutron-absorbing material at a given adequate speed from one of the channels into one of the storage bins.

Abstract: A multipole plasma pinch method and apparatus produces hot magnetically confined z-pinch plasma with a plurality of z-pinch current channels arranged so as to generate a multipolar magnetic field and at least one hyperbolic magnetic axis within the plasma space roughly enclosed by the channels, forming thereby a region of average magnetic well in a region of nested closed plasma magnetic surfaces surrounding the plasma current channels, when the magnetic field component in the direction of the hyperbolic axis is also made to be substantially zero in the vicinity of the hyperbolic axis. The multipole pinch invention may be operated so that q and field reversal take place within the plasma, and the plasma so produced closely approximates known theoretical stability conditions. The well-producing hyperbolic axis of the present invention is produced effectively by replacing the solid conducting rings of prior art multipole plasma confinement devices by z-pinch-like toroidal current channel loops of plasma.

Abstract: In one aspect, the invention is an improved pulsed-neutron monochromator of the vibrated-crystal type. The monochromator is designed to provide neutron pulses which are characterized both by short duration and high density. A row of neutron-reflecting crystals is disposed in a neutron beam to reflect neutrons onto a common target. The crystals in the row define progressively larger neutron-scattering angles and are vibrated sequentially in descending order with respect to the size of their scattering angles, thus generating neutron pulses which arrive simultaneously at the target. Transducers are coupled to one end of the crystals to vibrate them in an essentially non-resonant mode. The transducers propagate transverse waves in the crystal which progress longitudinally therein. The wave are absorbed at the undriven ends of the crystals by damping material mounted thereon. In another aspect, the invention is a method for generating neutron pulses characterized by high intensity and short duration.

Abstract: A device for collecting fission gas released by a failed fuel rod which device uses a filter to pass coolant but which filter blocks fission gas bubbles which cannot pass through the filter due to the surface tension of the bubble.

Abstract: A coherent radar including separate transmitting and receiving chains. The transmitting chain includes a master oscillator providing a signal at frequency F0. A multiplier multiplies F0 by a predetermined amount to produce a signal at a frequency F1. A second multiplier multiplies the signal at frequency F1 to produce a signal at frequency F2, F1 and F2 being coherent with F0. A first mixer mixes F1 with F0 and a second mixer mixes F2 with the product of the first mixer to produce a transmission signal. In the receiving chain, a received signal is amplified and filtered and then mixed in a third mixer with the second signal at frequency F2 from the transmitting chain. The mixing product of the third mixer is amplified and filtered and mixed in a fourth mixer with the first signal. The fourth mixer product is then coupled to a processor for producing a radar display.

Abstract: A seismic cable assembly having an acoustically transparent tubular enclosure has at least one hydrophone electrically connected and positioned within the cable assembly enclosure. The hydrophone is made up of a pair of formed, electrically conductive plates that fit against an insulating seal which also forms a fluid seal, providing a sealed chamber defined by the inside surfaces of the conductive plates. A pair of piezoelectric elements are interconnected and positioned within the sealed chamber, one element mechanically and electrically connected to the inside surface of one of the conductive plates and the other piezoelectric element mechanically and electrically connected to the inside surface of the other conductive plate. When pressure is applied to the conductive plates, they deform, causing the piezoelectric elements to flex. When the elements flex, an electrical output is presented on the conductive plates which serve as terminals.

Abstract: Control rods are inserted into the core of a nuclear reactor in operation to shut down the reactor output. Before completion of entire control rod insertion, a high-temperature coolant flowing in piping for a reactor water clean-up system is sprayed into the space in the upper portion of the reactor vessel. As the space is under negative pressure, oxygen existing in the water droplets of the sprayed coolant is separated. After completion of entire control rod insertion, a residual heat removal system is operated. The spraying operation is discontinued and a low-temperature coolant cooled by a heat exchanger in the residual heat removal system is sprayed into said space. The coolant sprayed by said first spraying operation is not cooled by the heat exchanger in said residual heat removal system.

Abstract: An apparatus for measuring the concentration of radioactivity in a radioactive fluid discharged from a nuclear power plant. The apparatus comprises a radioactivity concentration measurement pipe arranged to extend vertically, fluid supplying means for supplying the fluid into the measurement pipe in such a manner that the fluid flows down through the measurement pipe along the axis of the measurement pipe without contacting the inner surface of the latter, radioactivity concentration measuring means disposed at the outside of the measurement pipe for measuring the radioactivity concentration in the fluid flowing in the measurement pipe, and means for discharging the radioactive fluid to the outside of the measurement pipe. The apparatus further comprises a gas supply pipe opening at its one end to the atmosphere and communicated at its other end with the inside of the measurement pipe, and a check valve disposed in the gas supply pipe and operated at a pressure higher than the atmospheric pressure.

Abstract: A composite toroidal field (TF) generating means consisting of segmented magnetic coil windings is disclosed. Each coil winding of the TF generating means consists of a copper or copper alloy conductor segment and an aluminum or aluminum alloy conductor segment. The conductor segments are joined at a high strength, low electrical resistance joint and the joint may either be a mechanical or metallurgical one. The use of the aluminum or aluminum alloy conductor segments improves the neutron economy of the reactor with which the TF coil is associated and reduces TF coil nuclear heating and heating gradients, and activation in the TF coils.

Abstract: A pulse Doppler radar receiver which continuously monitors successively obtained amplitude values Ao through An with the disrupted amplitude values which deviate by a prescribed value from an interpolation value obtained from adjacent undisturbed amplitude values are determined and are limited to a value obtained from the interpolation value or from the largest or smallest adjacent undisrupted amplitude values and are substituted for the disrupted values. The apparatus includes an interpolation circuit which includes the shift register and limiter with the memory for adjusting the output signal level of the limiter.

Abstract: A seismic exploration method is disclosed for filtering the signals produced by a detector placed at different depths in a well in response to an emission of acoustic waves from a source on the surface: the signals comprising downgoing wave components and upgoing wave components.The filtering consists in sampling from among the N signals to be processed a group of n signals s.sub.1 . . . s.sub.n detected at respective levels x.sub.1 . . . x.sub.n, in determining the propagation time t.sub.k of the acoustic waves from the level x.sub.1 to each level x.sub.k, in both advancing and delaying the signals s.sub.k by the time t.sub.k in relation to s.sub.1, in adjusting the signals for the effects of the acoustic impedance of the formation, in combining s.sub.1 and the signals s.sub.k thus shifted and adjusted to obtain a sum z.sub.1 ', in calculating a sum y.sub.1 ' of s.sub.1 and of the thus delayed and adjusted signals s.sub.k, and in generating a signal u.sub.1.sup.

Abstract: A method for interchanging the frequency positions of n partial bands, each having a bandwidth b, of a signal frequency band, by the steps of: sampling signals in the frequency band at an input sampling rate; separating the sampled signals associated with each partial band into separate channels in stages in each of which sample signals are separated into high frequency and low frequency groups and the sampling rate is reduced; altering the positions of the channels in a scrambling matrix controlled by a random sequence generator; and spectrally recombining the signals in the separate channels into a signal extending across the signal frequency band.

Abstract: Methods and apparatus are disclosed for inhibiting the unauthorized copying of ROM-resident computer software or the like, for example, the audio-visual display of an electronic video game. A protection circuit including encryption/decryption means is coupled between the microprocessor and the ROM-memory and is operable in a first mode to properly encrypt/decrypt the program information according to a first algorithm and in a second mode to prevent proper encryption/decryption. The address-data buses are monitored by the protection circuit to detect an invalid program event, such as may occur when a microprocessor emulator is used to attempt an unauthorized copying or "dumping" of the program information. Upon detection of the invalid program event or "trap condition", the protection circuit switches to its second operating mode thereby to prevent copying of the decrypted program information.

Abstract: In the hydraulic fracturing of deep geologic formations for the production of fluid hydrocarbons, and where vertical fractures are formed, a method is described, using seismic geophysical techniques, for determining the azimuth and length of the fractures. This is accomplished by injecting into the formation through the fracture a selected fluid, or producing the fluid hydrocarbons from the formation into the fracture, until the formation, over a selected distance from the walls of the fracture, has a different gas saturation from the condition in the formation farther from the fracture. This condition is mapped by seismic methods.

Abstract: To remove the bottom nozzle of a nuclear fuel assembly, the nozzle plate must be disconnected from the control-rod thimbles. For nozzles whose control-rod thimbles are connected to the nozzle plate by screw fasteners having lock pins welded to the nozzle plate, a cutter for severing the welds is provided. The cutter is rotated by a motor at the work position through a long floating shaft. A long feed shaft operated by a thumb nut at the work position feeds the floating shaft and cutter downwardly through the weld. The bushings extend from a bushing plate, each encircling a screw fastener. Each bushing has a yieldable sleeve for sealing the region around a screw fastener to trap the chips from the severed weld. The cutter is indexed from weld to weld by indexing plates. To remove chips adhering to the cutter, the suction tube of a suction-pump-operated eductor is inserted in the auxiliary hole and the cutter is inserted in the bushing and chips are removed by suction.

Abstract: A seismic data gathering system includes a seismic cable having a plurality of cable sections, each including a seismic detector and a pair of signal lines for carrying the seismic energy signals produced by the detector in response to seismic energy waves. A shunting resistance is located in each cable section with one end connected to one of the pair of signal lines and the other end connected through a mating connector to the other of the pair of signal lines in the next succeeding cable section so that a shunting resistance is added to the seismic cable each time a detector is added to the seismic cable. In this manner the electrical damping of each seismic detector remains constant when the seismic cable is coupled to a data acquisition unit regardless of the number of detectors included within the seismic cable.